Dental arch space changes following premature loss of primary first molars: a systematic review

PURPOSE: The purpose of this study was to consider the available evidence regarding premature loss of primary molars and the implications for treatment planning. METHODS: Electronic database searches were conducted--including published information available until July 2007--for available evidence. A methodological quality assessment was also applied. RESULTS: Although a significant number of published articles had dealt with premature primary molar loss, only 3 studies (including a total combined sample of 80 children) had the minimal methodological quality to be considered for this systematic review. CONCLUSION: A reported immediate space loss of 1.5 mm per arch side in the mandible and 1 mm in the maxilla--when normal growth changes were considered--was found. The magnitude, however, is not likely to be of clinical significance in most cases. Nevertheless, in cases with incisor and/or lip protrusion or a severe predisposition to arch length deficiency prior to any tooth loss, this amount of loss could have treatment implications.     

Three-dimensional space changes after premature loss of a maxillary primary first molar

Background.  A space maintainer is generally preferred when a primary first molar is lost before or during active eruption of the first permanent molars in order to prevent space loss. However, controversy prevails regarding the space loss after eruption of the permanent first molars.
Aim.  The purpose of this study was to examine spatial changes subsequent to premature loss of a maxillary primary first molar after the eruption of the permanent first molars.
Design.  Thirteen children, five girls and eight boys, expecting premature extraction of a maxillary primary first molar because of caries and/or failed pulp therapy, were selected. Spatial changes were investigated using a three-dimensional laser scanner by comparing the primary molar space, arch width, arch length, and arch perimeter before and after the extraction of a maxillary primary first molar. Also, the inclination and angulation changes in the maxillary primary canines, primary second molars, and permanent first molars adjacent to the extraction site were investigated before and after the extraction of the maxillary primary first molar in order to examine the source of space loss.
Results.  There was no statistically significant space loss on the extraction side compared to the control side ( P  = 0.33). No consistent findings were seen on the inclination and angulation changes on the extraction side.
Conclusions.  The premature loss of a maxillary primary first molar, in cases with class I molar relationship, has limited influence on the space in permanent dentition.     

Twelve-month space changes after premature loss of a primary maxillary first molar

International Journal of Paediatric Dentistry 2011; 21: 161–166 Background. Many early investigations concerning space changes following premature extraction of primary molars had a cross‐sectional design, a small sample size, and a somewhat crude methodology, which may have led to misunderstandings. Aim. The aim of this study was to use established longitudinal data to investigate ongoing (12‐month) dental‐arch space problems arising as a result of premature loss of a primary maxillary first molar. Design. Thirteen children (mean ± SD age at time of tooth extraction, 6.0 ± 0.74 years) with unilateral premature loss of a primary maxillary first molar were selected for this study. Maxillary dental study casts were obtained from participants 2 or 3 days after the tooth was removed, as well as at a follow‐up appointment 12 months later. Six reference lines were measured on the study cast: D + E space, arch width, arch length, intercanine width, intercanine length, and arch perimeter. For each participant, the D + E space of the contralateral intact primary molar served as a control. A paired t‐test was used to compare the cast measurements between initial examination and 12‐month follow‐up. A t‐test was used to compare D + E space changes with those of the control group. Results. The D + E space of the extraction side after 12 months was significantly smaller than that of the control side (P < 0.05) and the initial D + E space (P < 0.05). A significantly greater arch perimeter, intercanine width, and intercanine length were found after 12 months compared with the initial parameters. No significant differences were found, however, in arch width or arch length between the initial examination and the 12‐month follow‐up examination (P > 0.05). Conclusions. The 12‐month space changes in the maxillary dental arch after premature loss of a primary maxillary first molar consist mainly of distal drift of the primary canine toward the extraction site. Mesial movement of permanent molars or tilting of the primary molars did not occur. An increased arch dimension was found especially in the anterior segment (intercanine width and length). There is no need for the use of space maintainers from the results in this study in cases of premature loss of a primary first molar.     

Immediate and six-month space changes after premature loss of a primary maxillary first molar

BACKGROUND: Premature loss of primary maxillary first molars has been associated with a number of consequences (such as tipping of the first permanent molar). The aim of the authors' study was to investigate dental-arch space problems arising as a result of premature loss of a primary maxillary first molar. METHODS: This study was composed of 19 children who experienced unilateral premature loss of a primary maxillary first molar. The authors used each patient's intact contralateral arch segment as a control. The authors obtained maxillary dental study casts two or three days after the tooth was extracted, as well as six months later. RESULTS: The D + E space from the extraction side six months after removal of the tooth (mean +/- standard deviation, 15.62 +/- 1.13 millimeters) was significantly smaller than the space on the control side (16.88 +/- 1.12 mm) and the initial D + E space (16.70 +/- 0.69 mm). The authors found a significantly shorter arch length (25.47 +/- 1.58 mm) and larger intercanine width (31.29 +/- 2.49 mm) six months after the tooth was extracted compared with the initial arch length (25.66 +/- 1.64 mm) and intercanine width (30.42 +/- 2.64 mm). CONCLUSIONS: The early space changes to the maxillary arch subsequent to premature loss of a primary maxillary first molar are primarily distal drift of the primary canines toward the extraction space and palatal migration of the maxillary incisors. Although 1 mm of space was lost, which is statistically significant, this is not likely to be of sufficient clinical significance to warrant use of a space maintainer. If palatal movement appears to be needed, the dentist should consider use of a palatal arch rather than a band-and-loop maintainer. CLINICAL IMPLICATIONS: The effects of space maintainers need to be re-evaluated in cases of unilateral premature loss of a primary maxillary first molar.     

The premature loss of primary first molars: Space loss to molar occlusal relationships and facial patterns

Objective:To investigate space changes with the premature loss of primary first molars and their relationship to permanent molar occlusion and facial forms.Materials and Methods:Two hundred twenty-six participants (ranging in age from 7 years 8 months to 8 years 2 months; 135 female, 91 male) met all inclusion criteria designed to study space loss as a result of the premature loss of the primary first molar. After 9 months, space loss was evaluated in relationship to molar occlusion and facial form. Statistical evaluation was performed with the paired t-test and with a two-way analysis of variance for independent groups.Results:Patients with leptoprosopic facial form and end-on molar occlusions all exhibited a statistically significant difference when compared to controls in terms of space loss (P < .001). The mandibular extraction site for individuals with a mesoprosopic/euryprosopic facial form and end-on molar occlusion displayed space loss as well (P < .05). All patients with a leptoprosopic facial form and Class I molar occlusion displayed space loss in the maxilla (P < .05) and the mandible (P < .001) respectively, that was statistically significant when compared to that of the control. Individuals within the mesoprosopic/euryprosopic group and with Class I molar occlusions showed no significant difference in space loss.Conclusions:The relationship between the first permanent molar occlusion and facial form of the child has an influence on the loss of space at the primary first molar site.     

Changes in the arch length following premature loss of deciduous molars

When the normal physiological process of deciduous tooth exfoliation and eruption of its successor is disrupted, a series of changes are observed in the dental arches. The aim of the study was to evaluate the amount of changes in arch length after the premature loss of deciduous molars. The sample consisted of 82 children, 53 without premature loss and 29 with premature loss of either deciduous first or second molar or both, unilaterally. A reduction in arch length was observed both in the maxilla and mandible at the molar region and an increase in arch length at the canine region in the mandible. Reduction in arch length was due to mesial migration of the molar and the increase in arch length was due to the distal migration of canine. It was seen that arch length reduction was more in maxilla as compared to the mandible and that distal drifting of canine was observed only in the mandible.     

Loss of space and changes in the dental arch after premature loss of the lower primary molar: a longitudinal study

The purpose of the study was to evaluate the space changes, dental arch width, arch length and arch perimeter, after the unilateral extraction of lower first primary molar in the mixed dentition period. A longitudinal study was conducted among forty children in the age group of 6-9 years, who reported for extraction of lower first primary molar in the department of Pedodontics, Govt. Dental College, Trivandrum. Study models were made from alginate impression taken before extraction and after extraction at the periodical intervals of two months, four months, six months and eight months. The mesiodistal width of lower first primary molar of the non-extracted side was taken as the control. The results of the study showed statistically significant space loss in the extraction side ( P value < 0.01) and no significant space loss in the control side (P value > 0.05). The rate of loss was greatest in the first four months. The arch width, arch length and arch perimeter had no significant change from initial to eight months follow up. The present study challenges the use of a space maintenance under the circumstances of premature loss of mandibular primary molar for preventing space loss.     

Long-term dental arch changes after rapid maxillary expansion treatment: a systematic review

This systematic review evaluates long-term dental arch changes after rapid maxillary expansion treatment on orthodontic patients with constricted arches. Clinical trials that assessed dental arch changes through measurements on dental casts or cephalometric radiographs were selected. No patients with surgical or other simultaneous treatment during the active expansion period were accepted. Electronic databases were searched with the help of a senior Health Sciences librarian. Original articles were retrieved from the selected abstracts, and their references were also scanned for possible missing articles. Forty-one articles met the initial inclusion criteria, but 35 were later rejected because they lacked a control group or only evaluated dental changes or used a semirapid technique. Some of them also lacked a reported measurement error. From the remaining articles, two did not report a long-term evaluation. From the final four articles, two measured changes through dental casts and two assessed changes through radiographs (one through lateral cephalometric radiographs and one through posteroanterior radiographs). Similar maxillary molar and cuspid expansion could be found in adolescents and young adults. Significantly less indirect mandibular molar and cuspid expansion was attained in young adults compared with adolescents. A significant overall gain in the maxillary and mandibular arch perimeter was found in adolescents. More transverse dental arch changes were found after puberty as compared with before, but the difference may not be clinically significant. No anteroposterior dental changes were found on lateral cephalometric radiographs.     

Management of ankylosed primary molars with premolar successors: A systematic review

BackgroundThe authors conducted a systematic review to determine the clinical prognosis of and methods of managing ankylosed primary molars with permanent successors.MethodsThe authors searched electronic databases (PubMed, Scopus, MEDLINE, Cumulative Index to Nursing and Allied Health Literature, Web of Science, Cochrane Database of Systematic Reviews and Google Scholar) up to April 2012 with the assistance of a librarian specializing in health sciences databases. They also searched the gray literature. They selected clinical studies in which investigators assessed the prognosis of ankylosed primary molars with permanent successors; they also hand searched references of the selected articles to identify any additional studies that the electronic search may have missed.ResultsThe authors identified 3,529 original articles from the electronic database search and none from the hand search. Once selection criteria were applied, only four articles met all inclusion criteria and were included. The number of patients studied ranged from 15 to 107. The number of ankylosed primary molars investigated ranged from 26 to 263.ConclusionsAnkylosed primary molars often manifest with mild to moderate progressive infraocclusion. Conservative monitoring of ankylosed primary molars is recommended. The clinician should consider extraction if the permanent successor has an altered path of eruption, if the ankylosed primary molar is severely infraoccluded with the adjacent teeth tipping to prevent the successor from erupting, or both. The ankylosed molar often exfoliates spontaneously within six months; however, when exfoliation is more delayed, arch-length loss, occlusal disturbance, hooked roots or impaction of permanent successors may occur.Practical ImplicationsAnkylosed primary molars initially should be monitored closely for up to six months. If they do not exfoliate spontaneously, they should be removed, because arch-length loss, alveolar bone defects, impacted permanent successors and occlusal disturbances often occur when the removal is delayed.     

Dental implant loss in older versus younger patients: a systematic review and meta‐analysis of prospective studies

The aim of this systematic review was to evaluate implant loss in younger and older patients. An electronic search of four databases (MEDLINE, EMBASE, SCOPUS and the Cochrane Library) was undertaken until May 2016 without time restriction and was supplemented by manual searching. Prospective cohorts were included if they met the following criteria: (i) presence of an exposed group (older subjects) with a minimum age of 60 years; (ii) presence of a control group (younger subjects) with a maximum age of 59 years; and (iii) outcome data considering implant survival or loss. Meta‐analyses were performed to evaluate the impact of ageing on implant failure. Of 4152 potentially eligible articles, four were included in the qualitative analysis and quantitative synthesis. The pooled estimates suggest that the risk of implant loss in older patients is not significantly higher (RR = 0·92; 95% CI 0·43–1·96, P = 0·83) when compared to younger subjects. This systematic review suggests that age is not a limiting factor for dental implant therapy.     

Efficacy of preformed metal crowns vs. amalgam restorations in primary molars: a systematic review

BACKGROUND: The authors evaluated the treatment efficacy of preformed metal crowns, or PMCs, vs. amalgam restorations in primary molars by means of a literature review and meta-analysis. TYPES OF STUDIES REVIEWED: From a literature search, the authors selected clinical studies that evaluated treatment with PMCs vs. amalgam control restorations in primary molars and provided data against which treatment outcomes could be compared. RESULTS: Ten studies with durations ranging from 1.6 to 10 years fulfilled the selection criteria. Their failure rates, based on need for subsequent treatment or retention of the restoration at final evaluation, ranged from 1.9 to 30.3 percent for PMCs and 11.6 to 88.7 percent for amalgam restorations. Overall, PMCs demonstrated greater longevity and reduced retreatment need compared with amalgam control restorations. The odds ratio for all studies fell within the boundary favoring treatment with PMCs. CLINICAL IMPLICATIONS: Analysis of the literature, though mainly retrospective studies, demonstrated evidence of a more favorable outcome for PMCs than for amalgam restorations in primary molars requiring multisurface restorations.     

Effect of mechanical debridement on distal periodontal aspects of second molars after the extraction of third molars: a systematic review

Background: The risk of periodontal defects after the extraction of third molars continues to challenge clinicians. Methods: Intervention trials, including subgingival scaling and/or root planing, were systematically reviewed. Data sources included the Cochrane Oral Health Group Trials Register and MEDLINE. The primary outcome was postoperative change in pocket probing depth (PD). Results: The electronic search yielded 751 abstracts, and manual searching added one study. From them, four trials fulfilled the inclusion criteria and were selected for review. The overall sample size of the studies was small, ranging from 15 to 30 participants. Only one trial was considered to present with low risk for bias in the sequence generation, the concealment of allocation to treatment, and the strategy for masking. The lack of information provided by the authors of the remaining studies resulted in unclear or high risk of bias for the chief dimensions of trial quality. The heterogeneity of the studies did not allow the use of meta‐analysis to summarize the results of several studies. Preliminary evidence originating from a small study suggests that ultrasonic root debridement of the second molar and a three‐visit plaque control program may have a beneficial effect on PD levels on the second molar. Conclusion: The available intervention trials on this topic have important limitations, and, consequently, there is insufficient evidence to recommend the use of mechanical debridement of second molars after the extraction of third molars.     

Dental flossing and interproximal caries: a systematic review

Our aim was to assess, systematically, the effect of flossing on interproximal caries risk. Six trials involving 808 subjects, ages 4 to 13 years, were identified. There were significant study-to-study differences and a moderate to large potential for bias. Professional flossing performed on school days for 1.7 years on predominantly primary teeth in children was associated with a 40% caries risk reduction (relative risk, 0.60; 95% confidence interval, 0.48-0.76; p-value, < 0.001). Both three-monthly professional flossing for 3 years (relative risk, 0.93; 95% confidence interval, 0.73-1.19; p-value, 0.32) and self-performed flossing in young adolescents for 2 years (relative risk, 1.01; 95% confidence interval, 0.85-1.20; p-value, 0.93) did not reduce caries risk. No flossing trials in adults or under unsupervised conditions could be identified. Professional flossing in children with low fluoride exposures is highly effective in reducing interproximal caries risk. These findings should be extrapolated to more typical floss-users with care, since self-flossing has failed to show an effect.     

Dental arch response to Haas-type rapid maxillary expansion anchored to deciduous vs permanent molars: A multicentric randomized controlled trial

Objective:To assess maxilla and mandibular arch widths'' response to Haas-type rapid maxillary expansion (RME) anchored to deciduous vs permanent molars on children with unilateral posterior crossbite.Materials and Methods:Seventy patients with unilateral posterior crossbite recruited at the Universities of Genova, Siena, and Insubria (Varese) were randomly located into GrE (RME on second deciduous molars) or Gr6 (RME on first permanent molars) and compared.Results:Upper intermolar distance and permanent molar angulation increased significantly in Gr6 vs GrE at T1. Upper intercanine distance increased significantly in GrE vs Gr6 at T1 and T2. GrE showed significant increases for upper intermolar and upper intercanine widths. Gr6 showed statistically significant increases for upper intermolar widths, for upper and lower intercanine widths, and for increases of angulation of upper and lower permanent molars.Conclusions:GrE showed reduced molar angulation increases at T1 and reduced molar angulation decreases at T2 when compared with Gr6. At T2, the net increase of the upper intercanine distance in GrE was still significant compared with Gr6, indicating a more stable expansion in the anterior area.     

Dental implants in growing patients: a systematic review

The aim of this systematic review (for which we followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines) was to provide an overview of the protocols and clinical outcomes of dental implants placed in growing jaws. We searched the MEDLINE/PubMed, Embase, Scopus, and Science Direct databases in October and November, 2017. A total of 3492 studies were identified, and all the studies reporting the outcomes of dental implants placed during the growth phase were included in the study.After duplicates had been removed, 2133 studies were screened based on their titles and abstracts, and 162 were selected for reading. Finally, 28 studies were included in the review. Overall, 493 dental implants were placed in 147 patients aged from 3–18 years old with follow-up being from 1–20 years. The most common disorders seen that were associated with missing teeth were ectodermal dysplasia and dental trauma. The main complications reported were the infraocclusion positioning of dental implants in the maxillary arch and the rotation of dental implants in the mandibular arch. Dental implants were indicated for the anterior regions of the maxilla and mandible in patients over 10 years old, and placement of maxillary implants in a more coronal position was recommended. Consultations and adjustments to prostheses were required until growth had ceased. In growing jaws, dental implants require positional modifications, and they should be considered only under special circumstances.